This invention relates to a portable self-erecting structure and, more particularly, the invention is concerned with providing a "pop-up" structure suitable for housing aircraft wherein a series of hydraulic elements which are an integral part of the structure, produce a relative rotation between adjacent structural elements resulting in the progressive erection of the composite structure.
Future requirements for tactical air power are expected to remain much as they are today -- rapid deployment, a timely weapon system application, and a quick and effective weapon system recovery and redeployment. Often, the site of deployment and air operations is a hostile zone, subject to random rocket and mortar attacks. Thus, for successful air operations, the appropriate weapons system support facilities must be included in the activity. These facilities should consist of easily transported and quickly erected shelters to give adequate weather protection and be expandable to a hardened structure, if needed, without hindering the mission.
The hereinafter described self-erecting aircraft shelter has many potential military applications. This structure and its construction technique provide for increased mobility and speed and ease of construction, combined with rapid recovery and efficient storage. Engineers with some imagination, by slightly modifying its configuration, could adapt the structure as a general-purpose space frame suitable for a number of military functions.
The possibility also exists of using this type of shelter on a very mobile basis to cover aircraft which are down for maintenance at remote installations or in severe weather conditions. The structure could be flown to the site of the downed aircraft, erected over it to provide shelter while maintenance was being performed, and then recovered when the work was finished.
Also, there are situations where a mobile installation must be converted to a permanent installation for sustained air operations. In many cases it is necessary to replace temporary structures with more durable ones because of extended time required for the mission. Obviously, this is uneconomical and may interrupt daily air operations. The pop-up shelter as it stands in the field in its soft-mobile form can be considered a soft-permanent structure. Its structural strength can be increased by explosively welding together all the hinged joints and hydraulic elements. For this operation, the explosives would be pre-positioned on the structure, go up with the elements to the desired erection mode, and detonate on command.
Mobile shelters should be suitable for conversion not only to soft-permanent structures without replacement or major modification, but also to hardened-permanent structures. This shelter is adaptable to that requirement. The basic structure explosively welded together can serve as the primary frame for a hardened structure. Instead of installing conventional roof panels which would provide only weather protection and insulation, a more shock-resistant panel could be installed. While precast concrete panels could easily be utilized, this would require heavy construction equipment at the job site, the elimination of which up to this point has been an advantage. To obviate this, hollow roof panels could be erected as integral components of the structure, and concrete pumped into them to form concrete panels.
A hardened shelter must be able to withstand mortar and rocket barrages as well as a general overpressure resulting from the application of more strategic weapons. Thus, for a hardened-permanent structure to be effective in withstanding dynamic loads, it must be able to deform enough to dissipate shock energy without deflection to failure. In this modification the concrete roof panels would be connected longitudinally at the truss points by embedded steel plates explosively welded together to form moment connectors. In addition, the hydraulic elements and connecting cables could be springloaded in a manner similar to that of a shock absorber to assist in dissipating shock energy.